1. Field of the Invention
The present invention relates generally to a vehicular velocity controlling apparatus for an automotive vehicle to control a vehicular driving force (or vehicular braking force but hereinafter referred to as the vehicular driving force only since the vehicular braking force is merely a negative value of the vehicular driving force) to make a present vehicular velocity of the vehicle substantially equal to a previously set target vehicular velocity (hereinafter, referred to a set vehicular velocity) and more particularly relates to the vehicular velocity controlling apparatus in which a modification technique of the set vehicular velocity is improved.
2. Description of the Related Art
A previous vehicular velocity controlling apparatus has been proposed in which three push button switches are aligned vertically along a peripheral surface of a vehicular steering wheel.
That is to say, a set/coast push button switch (hereinafter, referred to as a SET/COAST switch) is disposed at a lowest position of the three push button switches, a resume/accelerate push button switch (hereinafter, referred to as a RESUME/ACCELERATE switch) is disposed at an uppermost position thereof, and a cancel push button switch (hereinafter, referred to as a CANCEL switch) is disposed at a center position between the SET/COAST switch and the RESUME/ACCELERATE switch.
The SET/COAST switch serves as a switch enabled to set the set vehicular velocity Vset, to start such a vehicular velocity control as described above, and to decrease the set vehicular velocity value Vset. When a main switch of the previously proposed vehicular velocity controlling apparatus is turned on so that the vehicular velocity controlling apparatus falls in a vehicular velocity control wait state, the SET/COAST switch is pushed by a vehicular occupant for a short period of time (hereinafter, called a short-term push operation) so that the present vehicular velocity V is set as the set vehicular velocity Vset to start the vehicular velocity control. In addition, if the short-term push operation is carried out for the SET/COAST switch during the vehicular velocity control, the set vehicular velocity Vset is decreased by a predetermined velocity xcex94V (Vsetxe2x88x92xcex94V). If the SET/COAST switch is continued to be pushed (hereinafter, referred to as a continuous push operation or continuous operation) for a relatively long period of time during the vehicular velocity control, the set vehicular velocity Vset is decreased toward a lower velocity value at a predetermined deceleration.
On the other hand, the RESUME/ACCELERATE switch serves as a switch enabled to resume the vehicular velocity control and to increase the set vehicular velocity Vset toward a higher velocity value. If the short-term push operation is carried out for the RESUME/ACCELERATE switch during the vehicular velocity control, the set vehicular velocity Vset is increased toward the higher velocity value by a predetermined vehicular velocity xcex94V (Vset+xcex94V). If the continuous push operation is carried out for the RESUME/ACCELERATE switch during the vehicular velocity control, the set vehicular velocity Vset is increased toward the higher velocity value by a predetermined acceleration.
In addition, if the short-term push operation is carried out therefor with the vehicular velocity control released, the vehicular velocity control is resumed to make the vehicular velocity substantially equal to the set vehicular velocity Vset which is prior to the release of the vehicular velocity control.
Furthermore, the CANCEL switch serves as a switch enabled to release the vehicular velocity control.
On the other hand, in addition to the three push button switches described above, another vehicular velocity controlling apparatus has previously been proposed in which lever type switches are attached onto the peripheral surface of the steering wheel. When a lever of the lever type switches is pivoted by the vehicular occupant in a downward direction with respect to a vehicular body, the SET/COAST switch is turned on. When the lever is pivoted by the vehicular occupant in an upward direction with respect to the vehicular body, the RESUME/ACCELERATE switch is turned on.
Suppose that, in each of the previously proposed vehicular velocity controlling apparatuses as described above, the vehicular occupant depresses an accelerator pedal during a vehicular run by means of the vehicular velocity control. In this case, the vehicle is accelerated in response to the depression of the vehicular occupant on the accelerator pedal while the vehicular velocity control is temporarily halted. If the vehicular occupant depresses a brake pedal during the vehicular run by means of the vehicular velocity control, the vehicular velocity control is automatically released even if the CANCEL switch is not operated. It is noted that to RESUME the vehicular velocity control in this state, the RESUME/ACCELERATE switch may be operated.
On the other hand, a previous inter-vehicle distance controlling apparatus has been proposed in which the vehicular velocity is controlled to make an inter-vehicle distance from the vehicle to a preceding vehicle which is running ahead of the vehicle substantially equal to a previously set target inter-vehicle distance (hereinafter, referred to as a set inter-vehicle distance). In the previously proposed inter-vehicle distance controlling apparatus, the above-described vehicular velocity control function is included so that the set vehicular velocity Vset is set in addition to the set inter-vehicle distance. If the preceding vehicle is present in a front detection zone of the vehicle, the vehicular velocity V is controlled to follow up the preceding vehicle. If the preceding vehicle disappears from the front detection zone, the inter-vehicle distance control mode is automatically switched to the vehicular velocity control mode so that the vehicular driving force is controlled to make the vehicular velocity V substantially equal to the set vehicular velocity Vset.
However, in each of the above-described previously proposed vehicular velocity controlling apparatuses (the previous inter-vehicle distance controlling apparatus is included), when the set vehicular velocity Vset is modified using either one of the SET/COAST switch and RESUME/ACCELERATE switch, the operation of these switches is complex and troublesome, an operability thereof tends to be reduced, and it needs to carry out an operation which does not match with a general vehicular occupant""s sense of a vehicular manipulation.
It is, therefore, an object of the present invention to provide a vehicular velocity controlling apparatus for an automotive vehicle in which the modification for the set vehicular velocity Vset provides, without trouble, an operation which matches with the general vehicular occupant""s sense of the vehicular manipulation and which has improved the operability.
According to one aspect of the present invention, there is provided a vehicular velocity controlling apparatus for an automotive vehicle, comprising: a vehicular velocity detector to detect a vehicular velocity of the vehicle; a vehicular velocity controlling section that controls a vehicular driving force of the vehicle to make a detected value of the vehicular velocity substantially equal to a set vehicular velocity previously set; a plurality of switches including a first switch and a second switch, each switch being enabled to be interlocked with a predetermined operation of at least one switching member at a position such as to match with a general vehicular occupant""s sense of vehicular manipulation, the first switch being operated in response to the predetermined operation of the switching member at a first position such as to match with the general driver""s sense of vehicular manipulation to decrease the vehicular velocity, and the second switch being operated in response to the predetermined operation of the switching member at a second position such as to match with the general vehicular occupant""s sense of vehicular manipulation to increase the vehicular velocity; and a set vehicular velocity modifying section that modifies the set vehicular velocity in such a manner that the detected value of the vehicular velocity is set to the set vehicular velocity when at least one of the following conditions is established; when a time duration of the predetermined operation of the first switch is equal to or longer than a first predetermined time duration and the detected value of the vehicular velocity is lower than the set vehicular velocity and when the time duration of the predetermined operation of the second switch is equal to or longer than a second predetermined time duration and the detected value of the vehicular velocity is higher than the set vehicular velocity.
This summary of the invention does not necessarily describe all necessary features so that the invention may also be a sub-combination of these described features.